------------------------------------------------------------------------------ -- -- -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- -- -- -- S Y S T E M . T A S K _ P R I M I T I V E S . O P E R A T I O N S -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2004, Free Software Foundation, Inc. -- -- -- -- GNARL is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNARL is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNARL; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNARL was developed by the GNARL team at Florida State University. -- -- Extensive contributions were provided by Ada Core Technologies, Inc. -- -- -- ------------------------------------------------------------------------------ -- This is an Irix (old athread library) version of this package -- This package contains all the GNULL primitives that interface directly -- with the underlying OS. pragma Polling (Off); -- Turn off polling, we do not want ATC polling to take place during -- tasking operations. It causes infinite loops and other problems. with Interfaces.C; -- used for int -- size_t with System.Tasking.Debug; -- used for Known_Tasks with System.Task_Info; with System.Interrupt_Management; -- used for Keep_Unmasked -- Abort_Task_Interrupt -- Interrupt_ID with System.Parameters; -- used for Size_Type with System.Tasking; -- used for Ada_Task_Control_Block -- Task_Id with System.Program_Info; -- used for Default_Task_Stack -- Default_Time_Slice -- Stack_Guard_Pages -- Pthread_Sched_Signal -- Pthread_Arena_Size with System.Soft_Links; -- used for Defer/Undefer_Abort -- Note that we do not use System.Tasking.Initialization directly since -- this is a higher level package that we shouldn't depend on. For example -- when using the restricted run time, it is replaced by -- System.Tasking.Restricted.Stages. with System.OS_Primitives; -- used for Delay_Modes with System.Storage_Elements; -- used for To_Address with Unchecked_Conversion; with Unchecked_Deallocation; package body System.Task_Primitives.Operations is use System.Tasking.Debug; use System.Tasking; use Interfaces.C; use System.OS_Interface; use System.Parameters; use System.OS_Primitives; package SSL renames System.Soft_Links; ----------------- -- Local Data -- ----------------- -- The followings are logically constants, but need to be initialized -- at run time. Single_RTS_Lock : aliased RTS_Lock; -- This is a lock to allow only one thread of control in the RTS at -- a time; it is used to execute in mutual exclusion from all other tasks. -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List Environment_Task_Id : Task_Id; -- A variable to hold Task_Id for the environment task. Locking_Policy : Character; pragma Import (C, Locking_Policy, "__gl_locking_policy"); Clock_Address : constant System.Address := System.Storage_Elements.To_Address (16#200F90#); RT_Clock_Id : clockid_t; for RT_Clock_Id'Address use Clock_Address; ----------------------- -- Local Subprograms -- ----------------------- procedure Initialize_Athread_Library; function To_Task_Id is new Unchecked_Conversion (System.Address, Task_Id); function To_Address is new Unchecked_Conversion (Task_Id, System.Address); ----------------- -- Stack_Guard -- ----------------- -- The underlying thread system sets a guard page at the -- bottom of a thread stack, so nothing is needed. -- ??? Check the comment above procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is pragma Unreferenced (T); pragma Unreferenced (On); begin null; end Stack_Guard; -------------------- -- Get_Thread_Id -- -------------------- function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is begin return T.Common.LL.Thread; end Get_Thread_Id; ---------- -- Self -- ---------- function Self return Task_Id is begin return To_Task_Id (pthread_get_current_ada_tcb); end Self; --------------------- -- Initialize_Lock -- --------------------- -- Note: mutexes and cond_variables needed per-task basis are -- initialized in Initialize_TCB and the Storage_Error is -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...) -- used in RTS is initialized before any status change of RTS. -- Therefore rasing Storage_Error in the following routines -- should be able to be handled safely. procedure Initialize_Lock (Prio : System.Any_Priority; L : access Lock) is Attributes : aliased pthread_mutexattr_t; Result : Interfaces.C.int; begin Result := pthread_mutexattr_init (Attributes'Access); if Result = FUNC_ERR then raise Storage_Error; end if; if Locking_Policy = 'C' then Result := pthread_mutexattr_setqueueorder (Attributes'Access, MUTEX_PRIORITY_CEILING); pragma Assert (Result /= FUNC_ERR); Result := pthread_mutexattr_setceilingprio (Attributes'Access, Interfaces.C.int (Prio)); pragma Assert (Result /= FUNC_ERR); end if; Result := pthread_mutex_init (L, Attributes'Access); if Result = FUNC_ERR then Result := pthread_mutexattr_destroy (Attributes'Access); raise Storage_Error; end if; Result := pthread_mutexattr_destroy (Attributes'Access); end Initialize_Lock; procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is pragma Unreferenced (Level); Attributes : aliased pthread_mutexattr_t; Result : Interfaces.C.int; begin Result := pthread_mutexattr_init (Attributes'Access); if Result = FUNC_ERR then raise Storage_Error; end if; if Locking_Policy = 'C' then Result := pthread_mutexattr_setqueueorder (Attributes'Access, MUTEX_PRIORITY_CEILING); pragma Assert (Result /= FUNC_ERR); Result := pthread_mutexattr_setceilingprio (Attributes'Access, Interfaces.C.int (System.Any_Priority'Last)); pragma Assert (Result /= FUNC_ERR); end if; Result := pthread_mutex_init (L, Attributes'Access); if Result = FUNC_ERR then Result := pthread_mutexattr_destroy (Attributes'Access); raise Storage_Error; end if; Result := pthread_mutexattr_destroy (Attributes'Access); end Initialize_Lock; ------------------- -- Finalize_Lock -- ------------------- procedure Finalize_Lock (L : access Lock) is Result : Interfaces.C.int; begin Result := pthread_mutex_destroy (L); pragma Assert (Result = 0); end Finalize_Lock; procedure Finalize_Lock (L : access RTS_Lock) is Result : Interfaces.C.int; begin Result := pthread_mutex_destroy (L); pragma Assert (Result = 0); end Finalize_Lock; ---------------- -- Write_Lock -- ---------------- procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is Result : Interfaces.C.int; begin Result := pthread_mutex_lock (L); Ceiling_Violation := Result = FUNC_ERR and then errno = EINVAL; pragma Assert (Result /= FUNC_ERR); end Write_Lock; procedure Write_Lock (L : access RTS_Lock; Global_Lock : Boolean := False) is Result : Interfaces.C.int; begin if not Single_Lock or else Global_Lock then Result := pthread_mutex_lock (L); pragma Assert (Result = 0); end if; end Write_Lock; procedure Write_Lock (T : Task_Id) is Result : Interfaces.C.int; begin if not Single_Lock then Result := pthread_mutex_lock (T.Common.LL.L'Access); pragma Assert (Result = 0); end if; end Write_Lock; --------------- -- Read_Lock -- --------------- procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is begin Write_Lock (L, Ceiling_Violation); end Read_Lock; ------------ -- Unlock -- ------------ procedure Unlock (L : access Lock) is Result : Interfaces.C.int; begin Result := pthread_mutex_unlock (L); pragma Assert (Result = 0); end Unlock; procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is Result : Interfaces.C.int; begin if not Single_Lock or else Global_Lock then Result := pthread_mutex_unlock (L); pragma Assert (Result = 0); end if; end Unlock; procedure Unlock (T : Task_Id) is Result : Interfaces.C.int; begin if not Single_Lock then Result := pthread_mutex_unlock (T.Common.LL.L'Access); pragma Assert (Result = 0); end if; end Unlock; ----------- -- Sleep -- ----------- procedure Sleep (Self_ID : ST.Task_Id; Reason : System.Tasking.Task_States) is pragma Unreferenced (Reason); Result : Interfaces.C.int; begin if Single_Lock then Result := pthread_cond_wait (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access); else Result := pthread_cond_wait (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access); end if; -- EINTR is not considered a failure. pragma Assert (Result = 0 or else Result = EINTR); end Sleep; ----------------- -- Timed_Sleep -- ----------------- procedure Timed_Sleep (Self_ID : Task_Id; Time : Duration; Mode : ST.Delay_Modes; Reason : System.Tasking.Task_States; Timedout : out Boolean; Yielded : out Boolean) is pragma Unreferenced (Reason); Check_Time : constant Duration := Monotonic_Clock; Abs_Time : Duration; Request : aliased struct_timeval; Result : Interfaces.C.int; begin Timedout := True; Yielded := False; if Mode = Relative then Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time; else Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time); end if; if Abs_Time > Check_Time then Request := To_Timeval (Abs_Time); loop exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level or else Self_ID.Pending_Priority_Change; if Single_Lock then Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access, Request'Access); else Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access, Request'Access); end if; exit when Abs_Time <= Monotonic_Clock; if Result = 0 or Result = EINTR then -- somebody may have called Wakeup for us Timedout := False; exit; end if; pragma Assert (Result = ETIMEDOUT or else (Result = -1 and then errno = EAGAIN)); end loop; end if; end Timed_Sleep; ----------------- -- Timed_Delay -- ----------------- procedure Timed_Delay (Self_ID : Task_Id; Time : Duration; Mode : ST.Delay_Modes) is Check_Time : constant Duration := Monotonic_Clock; Abs_Time : Duration; Request : aliased struct_timeval; Result : Interfaces.C.int; begin -- Only the little window between deferring abort and -- locking Self_ID is the reason we need to -- check for pending abort and priority change below! SSL.Abort_Defer.all; if Single_Lock then Lock_RTS; end if; Write_Lock (Self_ID); if Mode = Relative then Abs_Time := Time + Check_Time; else Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time); end if; if Abs_Time > Check_Time then Request := To_Timeval (Abs_Time); Self_ID.Common.State := Delay_Sleep; loop if Self_ID.Pending_Priority_Change then Self_ID.Pending_Priority_Change := False; Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority; Set_Priority (Self_ID, Self_ID.Common.Base_Priority); end if; exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level; if Single_Lock then Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access, Request'Access); else Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access, Request'Access); end if; exit when Abs_Time <= Monotonic_Clock; pragma Assert (Result = 0 or else Result = ETIMEDOUT or else (Result = -1 and then errno = EAGAIN) or else Result = EINTR); end loop; Self_ID.Common.State := Runnable; end if; Unlock (Self_ID); if Single_Lock then Unlock_RTS; end if; pthread_yield; SSL.Abort_Undefer.all; end Timed_Delay; --------------------- -- Monotonic_Clock -- --------------------- function Monotonic_Clock return Duration is type timeval is record tv_sec : Integer; tv_usec : Integer; end record; pragma Convention (C, timeval); tv : aliased timeval; procedure gettimeofday (tp : access timeval); pragma Import (C, gettimeofday, "gettimeofday", "gettimeofday"); begin gettimeofday (tv'Access); return Duration (tv.tv_sec) + Duration (tv.tv_usec) / 1_000_000.0; end Monotonic_Clock; ------------------- -- RT_Resolution -- ------------------- function RT_Resolution return Duration is begin return 10#1.0#E-6; end RT_Resolution; ------------ -- Wakeup -- ------------ procedure Wakeup (T : ST.Task_Id; Reason : System.Tasking.Task_States) is pragma Unreferenced (Reason); Result : Interfaces.C.int; begin Result := pthread_cond_signal (T.Common.LL.CV'Access); pragma Assert (Result = 0); end Wakeup; ----------- -- Yield -- ----------- procedure Yield (Do_Yield : Boolean := True) is begin if Do_Yield then pthread_yield; end if; end Yield; ------------------ -- Set_Priority -- ------------------ procedure Set_Priority (T : Task_Id; Prio : System.Any_Priority; Loss_Of_Inheritance : Boolean := False) is pragma Unreferenced (Loss_Of_Inheritance); Result : Interfaces.C.int; begin T.Common.Current_Priority := Prio; Result := pthread_setprio (T.Common.LL.Thread, Interfaces.C.int (Prio)); pragma Assert (Result /= FUNC_ERR); end Set_Priority; ------------------ -- Get_Priority -- ------------------ function Get_Priority (T : Task_Id) return System.Any_Priority is begin return T.Common.Current_Priority; end Get_Priority; ---------------- -- Enter_Task -- ---------------- procedure Enter_Task (Self_ID : Task_Id) is Result : Interfaces.C.int; begin Self_ID.Common.LL.Thread := pthread_self; Self_ID.Common.LL.LWP := sproc_self; Result := pthread_set_ada_tcb (Self_ID.Common.LL.Thread, To_Address (Self_ID)); pragma Assert (Result = 0); Lock_RTS; for J in Known_Tasks'Range loop if Known_Tasks (J) = null then Known_Tasks (J) := Self_ID; Self_ID.Known_Tasks_Index := J; exit; end if; end loop; Unlock_RTS; end Enter_Task; -------------- -- New_ATCB -- -------------- function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is begin return new Ada_Task_Control_Block (Entry_Num); end New_ATCB; ------------------- -- Is_Valid_Task -- ------------------- function Is_Valid_Task return Boolean is begin return False; end Is_Valid_Task; ----------------------------- -- Register_Foreign_Thread -- ----------------------------- function Register_Foreign_Thread return Task_Id is begin return null; end Register_Foreign_Thread; -------------------- -- Initialize_TCB -- -------------------- procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is Result : Interfaces.C.int; Cond_Attr : aliased pthread_condattr_t; begin if not Single_Lock then Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level); end if; Result := pthread_condattr_init (Cond_Attr'Access); pragma Assert (Result = 0 or else Result = ENOMEM); if Result = 0 then Result := pthread_cond_init (Self_ID.Common.LL.CV'Access, Cond_Attr'Access); pragma Assert (Result = 0 or else Result = ENOMEM); end if; if Result = 0 then Succeeded := True; else if not Single_Lock then Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access); pragma Assert (Result = 0); end if; Succeeded := False; end if; Result := pthread_condattr_destroy (Cond_Attr'Access); pragma Assert (Result = 0); end Initialize_TCB; ----------------- -- Create_Task -- ----------------- procedure Create_Task (T : Task_Id; Wrapper : System.Address; Stack_Size : System.Parameters.Size_Type; Priority : System.Any_Priority; Succeeded : out Boolean) is Attributes : aliased pthread_attr_t; Adjusted_Stack_Size : Interfaces.C.size_t; Result : Interfaces.C.int; function Thread_Body_Access is new Unchecked_Conversion (System.Address, start_addr); function To_Resource_T is new Unchecked_Conversion (System.Task_Info.Resource_Vector_T, System.OS_Interface.resource_t); use System.Task_Info; begin if Stack_Size = Unspecified_Size then Adjusted_Stack_Size := Interfaces.C.size_t (System.Program_Info.Default_Task_Stack); elsif Stack_Size < Minimum_Stack_Size then Adjusted_Stack_Size := Interfaces.C.size_t (Minimum_Stack_Size); else Adjusted_Stack_Size := Interfaces.C.size_t (Stack_Size); end if; Result := pthread_attr_init (Attributes'Access); pragma Assert (Result = 0 or else Result = ENOMEM); if Result /= 0 then Succeeded := False; return; end if; Result := pthread_attr_setdetachstate (Attributes'Access, 1); pragma Assert (Result = 0); Result := pthread_attr_setstacksize (Attributes'Access, Adjusted_Stack_Size); pragma Assert (Result = 0); if T.Common.Task_Info /= null then Result := pthread_attr_setresources (Attributes'Access, To_Resource_T (T.Common.Task_Info.Thread_Resources)); pragma Assert (Result /= FUNC_ERR); if T.Common.Task_Info.Thread_Timeslice /= 0.0 then declare use System.OS_Interface; Tv : aliased struct_timeval := To_Timeval (T.Common.Task_Info.Thread_Timeslice); begin Result := pthread_attr_set_tslice (Attributes'Access, Tv'Access); end; end if; if T.Common.Task_Info.Bound_To_Sproc then Result := pthread_attr_set_boundtosproc (Attributes'Access, PTHREAD_BOUND); Result := pthread_attr_set_bsproc (Attributes'Access, T.Common.Task_Info.Sproc); end if; end if; -- Since the initial signal mask of a thread is inherited from the -- creator, and the Environment task has all its signals masked, we -- do not need to manipulate caller's signal mask at this point. -- All tasks in RTS will have All_Tasks_Mask initially. Result := pthread_create (T.Common.LL.Thread'Access, Attributes'Access, Thread_Body_Access (Wrapper), To_Address (T)); pragma Assert (Result = 0 or else Result = EAGAIN); Succeeded := Result = 0; Set_Priority (T, Priority); Result := pthread_attr_destroy (Attributes'Access); pragma Assert (Result /= FUNC_ERR); end Create_Task; ------------------ -- Finalize_TCB -- ------------------ procedure Finalize_TCB (T : Task_Id) is procedure Free is new Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id); Result : Interfaces.C.int; Tmp : Task_Id := T; begin if not Single_Lock then Result := pthread_mutex_destroy (T.Common.LL.L'Access); pragma Assert (Result = 0); end if; Result := pthread_cond_destroy (T.Common.LL.CV'Access); pragma Assert (Result = 0); if T.Known_Tasks_Index /= -1 then Known_Tasks (T.Known_Tasks_Index) := null; end if; Free (Tmp); end Finalize_TCB; --------------- -- Exit_Task -- --------------- procedure Exit_Task is Result : Interfaces.C.int; begin Result := pthread_set_ada_tcb (pthread_self, System.Null_Address); pragma Assert (Result = 0); end Exit_Task; ---------------- -- Abort_Task -- ---------------- procedure Abort_Task (T : Task_Id) is Result : Interfaces.C.int; begin Result := pthread_kill (T.Common.LL.Thread, Interfaces.C.int (System.Interrupt_Management.Abort_Task_Interrupt)); pragma Assert (Result = 0); end Abort_Task; ---------------- -- Check_Exit -- ---------------- -- Dummy version function Check_Exit (Self_ID : ST.Task_Id) return Boolean is pragma Unreferenced (Self_ID); begin return True; end Check_Exit; -------------------- -- Check_No_Locks -- -------------------- function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is pragma Unreferenced (Self_ID); begin return True; end Check_No_Locks; ---------------------- -- Environment_Task -- ---------------------- function Environment_Task return Task_Id is begin return Environment_Task_Id; end Environment_Task; -------------- -- Lock_RTS -- -------------- procedure Lock_RTS is begin Write_Lock (Single_RTS_Lock'Access, Global_Lock => True); end Lock_RTS; ---------------- -- Unlock_RTS -- ---------------- procedure Unlock_RTS is begin Unlock (Single_RTS_Lock'Access, Global_Lock => True); end Unlock_RTS; ------------------ -- Suspend_Task -- ------------------ function Suspend_Task (T : ST.Task_Id; Thread_Self : Thread_Id) return Boolean is begin if T.Common.LL.Thread /= Thread_Self then return pthread_suspend (T.Common.LL.Thread) = 0; else return True; end if; end Suspend_Task; ----------------- -- Resume_Task -- ----------------- function Resume_Task (T : ST.Task_Id; Thread_Self : Thread_Id) return Boolean is begin if T.Common.LL.Thread /= Thread_Self then return pthread_resume (T.Common.LL.Thread) = 0; else return True; end if; end Resume_Task; ---------------- -- Initialize -- ---------------- procedure Initialize (Environment_Task : Task_Id) is begin Environment_Task_Id := Environment_Task; Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level); -- Initialize the lock used to synchronize chain of all ATCBs. Enter_Task (Environment_Task); Set_Priority (Environment_Task, Environment_Task.Common.Current_Priority); end Initialize; -------------------------------- -- Initialize_Athread_Library -- -------------------------------- procedure Initialize_Athread_Library is Result : Interfaces.C.int; Init : aliased pthread_init_struct; package PINF renames System.Program_Info; package C renames Interfaces.C; begin Init.conf_initsize := C.int (PINF.Pthread_Arena_Size); Init.max_sproc_count := C.int (PINF.Max_Sproc_Count); Init.sproc_stack_size := C.size_t (PINF.Sproc_Stack_Size); Init.os_default_priority := C.int (PINF.Os_Default_Priority); Init.os_sched_signal := C.int (PINF.Pthread_Sched_Signal); Init.guard_pages := C.int (PINF.Stack_Guard_Pages); Init.init_sproc_count := C.int (PINF.Initial_Sproc_Count); Result := pthread_exec_begin (Init'Access); pragma Assert (Result /= FUNC_ERR); if Result = FUNC_ERR then raise Storage_Error; -- Insufficient resources end if; end Initialize_Athread_Library; -- Package initialization begin Initialize_Athread_Library; end System.Task_Primitives.Operations;